It is known that certain diseases can be prevented and treated by inhibition of cell adhesion as such pathological relationship comes to be increasingly clear. Some cell adhesion molecules are involved in cell adhesion, and VLA-4 is known as a molecule having a role in mediating adhesion of leukocytes. On the basis of this knowledge, a variety of VLA-4 inhibitors have been developed. Patent document 1 discloses a compound which exhibits excellent VLA-4 inhibitory activity and thus is useful as a preventive and/or therapeutic drug for disorders caused by cell adhesion.
Example 170 of Patent document 1 discloses that trans-4-[1-[2,5-dichloro-4-[(1-methyl-1H-3-indolylcarbonyl)amino]phenylacetyl]-(4S)-methoxy-(2S)-pyrrolidinylmethoxy]cyclohexanecarboxylic acid (hereinafter referred to as compound (a)) was isolated as a colorless solid.
[Patent document 1] WO 02/053534